Radiation-induced DNA damage and lethality in E. coli as modified by the antitumor agent cis-dichlorodiammineplatinum (II).
Radiation-induced DNA damage and lethality in E. coli as modified by the antitumor agent cis-dichlorodiammineplatinum (II).
复制标题
经抗肿瘤剂顺式二氯二氨铂 (II) 修饰后，辐射诱导的大肠杆菌 DNA 损伤和致死率。
作者：
R. Richmond;J. Zimbrick;D. Hykes
本文报道了顺式Pt（NH/sub 3/）/sub 2/Cl/sub 2/在大肠杆菌静止期细胞上的抗肿瘤作用。大肠杆菌C的毒性，辐射敏化，和辐射诱导的胸腺嘧啶碱基残留从细胞DNA的释放的影响。在N/sub 2/-饱和悬浮液中的敏化比在O/sub 2/-饱和悬浮液中获得的敏化大约60%。此外，低剂量辐射敏感性的一个小组件被观察到的细菌照射在敏化浓度的Pt络合物的存在下缺氧，但不是好氧，条件。当含有3 H-胸腺嘧啶标记的DNA的稳定期细胞在设计抑制酶作用的条件下被照射和处理时，从细胞DNA中获得各种氚化产物。最高产量的产品已被确定为胸腺嘧啶，和更多的胸腺嘧啶产生时，有氧气存在的照射过程中比当它是不存在的。当细胞在存在敏化浓度的铂药物的情况下被照射时，胸腺嘧啶产率降低，并且在好氧和缺氧条件之间显示出很小的差异。
The antitumor drug, cis-Pt(NH/sub 3/)/sub 2/Cl/sub 2/, has been tested on stationary phase cells of E. coli C for toxicity, radiation sensitization, and effect on radiation-induced thymine base residue release from cellular DNA. Sensitization in N/sub 2/-saturated suspensions is about 60% greater than that obtained in O/sub 2/-saturated suspensions. Additionally, a small component of low-dose radiation sensitivity is observed for bacteria irradiated in the presence of sensitizing concentrations of the Pt complex under anoxic, but not oxic, conditions. When stationary phase cells which contain /sup 3/H-thymine-labeled DNA are irradiated and treated under conditions designed to inhibit enzyme action, various tritiated products are obtained from the cellular DNA. The product of highest yield has been identified as thymine, and more thymine is produced when oxygen is present during irradiation than when it is absent. When cells are irradiated in the presence of a sensitizing concentrations of the platinum drug, the thymine yield is reduced and shows little difference between oxic and anoxic conditions.